Daniel dkawbaugh



(No MEdel.)

D.DRAWBAUGH.

TELEPHONE. No. 303,629. Patented Aug. 19, 1884.

WITNESSES INVENTOR M Ma ATTORNEY DANIEL DRAWBAUGH, OF EBERLY S MILL, PENNSYLVANIA, ASSIGNOR TO THE PEOPLES TELEPHONE COMPANY, OF NEV YORK.

TELEPHONE. I

SPECIFICATION forming part of Letters Patent No. 303,629, dated August 19, 1884'.

Application filed March 29, 1884. (No model.)

To all whom it "may concern-.-

Be it known that I, DANIEL DRAWBAUGH,

of Eberlys Mill, Cumberland county, Pen sylvania, have invented provement in ing is a specification.

The invention consists in a receivingteleof membrane or phone having a diaphragm similar material, to whiclran armature magnetic material is secured, and also containing an electro-magnet ad j ustably secured Figure 1 Fi Similar letters of reference represent like parts.

A is the base-board, to which is secured, by

a strap of metal, 0, a hollow cylindrical bo B.

cord, H, or by any other suitable means,

diaphragm, D, of membrane or like material,

to the center of which diaphragm is secure in any convenient way, an armature, E, magnetic material.

F is an electro-magnet, having its poles facarmature E. Said magnet rests upon a supporting-block, G. Upon the upper side Through ing the of the elect-ro-magnet is a bar, I. this bar and into the supporting-block passes a screw, the magnet is 110 near to or farther from the armature.

ened, thus holding said v K is a piece of spring metal containing slot, L, through which passes a new and useful Im- Telephones,of which the followas more fully here- To one end of this box is attached, by a J. By loosening this screw longer tightly held to the block, and therefore may be adjusted by hand \V hen the magnet is so adjusted, the screw J is tightmagnet firmly in place.

the screw M,

enters the baseboard A. One K is bent upward and bears D. A recess is made on in Fig. 3,

which screw end of the spring against the diaphragm the lower side of block G, as shown to allow of passage of the spring. When the screw M is loosened,the spring K may be adjusted to bear with greater or less pressure upon the diaphragm D., and the spring may be secured, after being adjusted in any desired position, by tightening the screw M. The spring K thus serves as a means of regulating the tension of the diaphragm.

At N are the ends of the wire forming the coil of the eleetro'magnet, to which ends the circuit-wires are attached.

I claim as my invention- 1. In combination with the membrane diaphragm of a telephone, a spring for regulating the tension of said diaphragm, interposed between the diaphragm and a support, and pressing upon the diaphragm.

2. In G nbination with the membrane di aphragiii an adjustable spring for regulating the tension of the diaphragm, interposed between the diaphragm and a support, and p ressing upon the diaphragm.

3. In combination with the membrane di aphragm, its attached armature, and'the elec- Witnesses:

PARK BENJAMIN, J. B. Cannon.

tro-magnet, a spring bearing against the di- 

